Updated

The former CEO who oversaw the West Virginia mine that exploded in 2010, killing 29 people, was indicted Thursday on federal charges related to a mine safety investigation that followed the blast.

U.S. Attorney Booth Goodwin said a federal grand jury indicted former Massey Energy CEO Don Blankenship on charges that include conspiracy to violate mandatory federal mine safety and health standards, conspiracy to impede federal mine safety officials, making false statements to the Securities and Exchange Commission and securities fraud.

Blankenship could face up to 31 years in prison if convicted.

The indictment alleges Blankenship conspired to violate mine safety and health standards at the Upper Big Branch Mine from January 2008 until April 2010, when an explosion at the mine killed 29 coal miners.

Specifically, the indictment said Blankenship was part of a conspiracy to provide advance warning of federal mine safety inspections, allowing mine bosses to conceal and cover up safety violations.

After the explosion, Blankenship made false statements and representations to the SEC concerning Massey Energy's safety practices prior to the explosion. He made similar statements in connection with the purchase and sale of Massey Energy stock, the indictment said.

Alpha Natural Resources bought Massey for $7.1 billion in June 2012. Blankenship, who retired ahead of the merger, has denied any wrongdoing

Four investigations into the Upper Big Branch explosion found that worn and broken cutting equipment created a spark that ignited accumulations of coal dust and methane gas. Broken and clogged water sprayers allowed what should have been a minor flare-up to become an inferno.

The federal Mine Safety and Health Administration said the root cause was Massey's "systematic, intentional and aggressive efforts" to conceal life-threatening problems. MSHA said managers even maintained two sets of pre-shift inspection books — an accurate one for themselves, and a sanitized one for regulators.